Dash-pot.



E. E.THOMAS.

DASH POT.

APPLICATION FILED JULY 5.1913.

Patented Nov. 21, 1916.

Wit/7 e55 es r m m m OFFICE.

EDWIN E. THOMAS, OF PORTLAND, OREGON, ASSIG-NOR TO HARRY O. TENNEY, OF

' PORTLAND, OREGON.

DASH-POT.

Application filed July 5, 1913. Serial No. 777,485.-

To all whom it may concern:

Be it known that I, EDWIN E. THOMAS, a citizen of the United States,residing in thecity of Portland, county of Multnomah, and State ofOregon, have inventedcertain new and useful Improvements inDash-Pots,,of which the following is a specification.

My invention relates to power cylinders with oil control, and moreparticularly to improvements whereby I am able to get a steady anduniformforward thrust with a quick return of the operating piston. Iaccomplish this by means of a double cylinder construction, one of whichcylinders is the power cylinder with its piston working therein, and theother cylinder of which is provided with a piston and has its oppositeends connected, whereby a heavy fluid filling the same is forced fromone end of the cyl-'v inder to the other and back again withfeach strokeof said piston. A limitedor restrict- 'ed, passageway tpermits. thefluid to pass from one end the cylinder to the other in one direction,while a more open passageway permits its return, thereby affording aretarding or controlling effect upon the piston when traveling in onedirection, and permitting a free and quick return of the piston in theopposite direction.

In prder that others may fully understand my invention, I haveillustrated one practical embodiment thereof on the accompanying sheetof drawings, which I will now describe. The view is a side elevation ofthis embodiment of the invention, and illustrates such a power cylinderas might be used in operating a reciprocating saw, or the like.

. Referring now to the drawings, the invention is mounted upon asuitable base or support 1, and comprises a double cylinder structurewith a steam cylinder 2 and an oil 'cylinder 3, having pistons 4 and 5,respectively, shown in dotted lines, working therein. The steam piston 4operates a piston rod 6 while the oil piston 5, operates a piston rod orshaft 7, projecting from said oil cylinder?) at both ends thereof, asindicated, said piston rods 6 and 7 .being connected with an operatinghead 8, with which is connected any suitable driving rod, as 9. The oilpiston rod 7 is provided with an adjustable bumper block, as 10, adaptedto engage a bumper head, as 11', provided on its outer face with arubber or other suitable cushioning material. At the opposite end ofsaid oil cylinder 3, is another bumper head 12, against which the upperpart of the connecting head can operate as a bumper block, and to thisend said head is also made adjustable upon the piston rod 7 asindicated.

Mounted upon the side of said steam cylinder 2, is a steam chest andvalve mechanism, as 13, having connecting pipes,-as 14 and 15, to theopposite ends ofsaid steam cylinder, with a steam supply pipe 16 leadingthereto, and an exhaust pipe, as 17, leading therefrom, as indi cated. Avalve member 18 in said steam chest controls the admission of steamtherefrom to the opposite ends of said steam cylinder, and this Valvemember is operated by a valve rod 18, connected at its outer end with arocking lever 19, which is connected at its lower end by means of a rodor link 20, to a foot lever 21.

Patented Nov. 21, 1916.

operates to normally return and'hold'said valve rod and thevalve withinsaid steam chest in position to admit steam to one end of said steamcylinder, whereby to drive the steam piston to the opposite end thereof.By pressing upon the foot lever 21, said valve can be moved so as toadmit steam to the opposite end of said cylinder and to open the otherend thereof to the exhaust, as will be understood from the dotted lineshowing of the valve member and the connecting parts. These features,however, are old and are not claimed as a part of this invention, exceptas they perform their regular functions in combination with the featuresnow to be described.

Referring now to the .upper part of the drawing, A designates an oiltank connected with the oil cylinder 3 in a direct line by the use ofstandard fittings, as indicated, 23 being a check valve interposedtherein. The opposite end of said oil cylinder, 3, is connected by meansof a double pipe line, as 2-125, said pipes having interposed thereincocks, as 24 and 25, adapted to be adjusted right, as shown in thedrawings, this being the power stroke, theoil piston, being connectedtherewith must also move with it. This'movement of said pistons is moreor less retarded and made steady and evenby reason of the oil in theoilpistonbeing,

forced through pipe 25, only, to the opposite end of said cylinder, asindicated by the arrowsgThe cock 25, it will'be understood, canbe'regulatedso as to give the right retarding eflect upon the forward orpower stroke of the pistons. As the pistons are re- 1 turned, the oil'isfree to pass through both pipes 24 and 25 from the left hand end of theoil cylinder to the right hand end thereof, and by reason of thisgreater passageway, the oil passes freely and affords practically noretarding effect, thereby permitting a.

. and the check valve 23 prevents the oil from being forced upwardlyinto ,the tank during the strokeof the pistons. v

Thus by means of a construction where a quantity of oil must be forcedthrough a restricted opening from one point to another,

and is returnable through a more open passageway, I am able to controlthe forward or power stroke of a power cylinder and to permit of a quickreturn of the of, as hereinbefore described.

I am aware that changes can be made in the construction 'hereshown forpurposes of illustration without departing from the spirit of theinvention, and I do not, therefore, limit the invention to this showing,except as I may be limited by the" hereto appended claims, forming apart hereof.

I claim:

piston there- .1. A cushioning means for power-actumechanlsm, comprlslnatedmechanism, comprising in combination a cyllnder, a plston thereln, afluid 1n said cylinder, ports at. opposite ends of said cylinder, meansconnecting said orts with each other around said piston fo'rmingtwopassageways therebetweengand a check valve in one of said passageways,whereby to permit passage of fluid therethrough in one direction only. 1

2. A cushioning means for power-actuated'mechanism, comprising incombination a cylinder, a piston therein, a fluid in said cylinder, aport through the side of sald cylinder at each end thereof, and twopipes connected together at their opposite ends and connected .into saidports, one of said pipes beingprovided wlth a check valve therein,whereby, to permit the passage of fluid therethrough in onesubstantially asdescribed.

3. A cushioning'means for power-actubeing provided with a check valvetherein,

whereby to permit the passage of fluid therethrough in one directiononly, andthe other direction only,-

of said pipes being provided with a valve for regulating the size of thepassageway therethrough, substantially as described.

. 4. A cushioning means 'for power-actuated mechanism, comprising incombination a cylinder, a piston adapted to work therein,

a fluid in said cylinder, outlet pipes from the opposite ends of saidcylinder, two connect ing pipes of less area connecting said outletpipes together to form a double'by-pass between said outlet pipes, oneof said conne'cting pipes being provided with a check valve, whereby toprevent passage therethrough in one direction, while permitting passagetherethrough in the opposite direction, and

the other of said connecting pipes being provided with a controllingcock, substantially as described.

5. A cushioning means for power-actuated mechanism, comprising incombination a cylinder, pipe connecting ports at opposite ends of saidcylinder, means forming a double passageway'and connectingsaid portstogether, one of said passageways being pro vided with a check valve toprevent passage therethrough in one direction,and a reservoir for fluidconnected with said pipes with j a check valve interposed in saidconnection,

whereby. to maintain a proper supply of fluid in said pipes and saidcylinder, substantially as described.

6. A cushioning means for power-actuatedv a cylinder, a piston adaptedto work therein, a fluid in said cylinder, outlet pipes fromtheopposlte'ends of said cylinders, two connectirigpipes of less. areaconnecting said outlet plpes together-v to form a by-pass from one endof the cylinder to the other, one of said connecting pipes beingprovided with a check valve, whereby to prevent passage therethrough inone direction, while permitting passage therethrough in the oppositedirection, substantially as described. 1

EDWIN .E. THOMAS.

In presence of- G. A. NIoHoLs,

OMA L. DAY.

